Sparking plug for internal-combustion engines



Oct. 21. 1924.'

, M. A. GRAY SPARKING PLUG FOR INTERNAL COMBUSTION ENGINES Filed April 29. 1922 Patented Get. 2l., ld.

UNITED STATES Vy'IALCOLlVlI ALLAN GRAY, OF BRIXTON, LONDON, ENGLAN-D.

SPARKING :PLUG FOR INTERNAL-COMBUSTION ENGlNES.

Application filed ApriI 29,

To all 'whom t may concern:

Be it known that l, MALCOLM ALLAN GRAY, residing at Brixton, London, England, a subject of the,` King of Great Britain and Ireland, have invented certain new and useful Improvements in Sparking Plugs for lnternal-Combustion Engines, of which the following is a specification.

This invention relates to sparking plugs for internal combustion engines and the 0bject is to provide a novel combination priming and self-cleaning plug, that is to say, a

plug which is provided both with means of a novel character for feeding a priming charge of liquid fuel to the combustion chamber of the cylinder and these means, or part of saine,'serving at the same time to open communica-tion between the combustion chamber and the atmosphere whereby the pressure of air or gases in the combustion chamber may blow back or through the plug to clear the electrode or electrodes and insulating member of carbon or other deposits which in ay adhere thereto.

lVith this object in view the invention comprises a. construction whereby on axially rotating one member of the plug in relation to another, it will act as a valve to open and close ai number of passages all round the insulated electrode of the plug so that communication is afforded between the atmosphere and combustion chamber of the cylinder respectively, and there is Afitted to the lower member ofthe plug and surrounding the valve a vessel or cupi to receivey liquid fuel, which on opening of the passages as above-mentioned will permit the llo-w of said liquid fuel therethrough into the cylinder, thus dispensing with the usual priming cocks and the like. The same passages which serve for the flow of said priming fuel also serve for the blow back or flow' of air or gases under pressure from the cylinder to the atmosphere so that such air or gases will dislodge and remove any solid particles or matter or oil which collects on the electrodes and insulation thus avoiding the usual cause of short-circuits.

An embodiment of the invention is illustratcd by way of example, in the accompanying drawings in which Fig. l is a half elevation, half vertical section of the plug with the parts in normal or closed position;

l*1 ig. 2 isa similar view with the parts in open or priming and self-cleaning position;

1922. serial No. 557,445.

Fig.V 3 is a; sectional detail view of the lower plug member;

Fig. 4 is a sectional detail view of the valve seat member;

Fig. 5 is a detail elevation thereof;

F ig. 6 is a cross section on the line 6-6 of Fig. 5, and

Fig. 7 is a partial sectional view showing the improved plug applied to the cylinder of an internal combustion engine.

The improved plug as shown in the drawings comprises a lower member or hollow plug c which is exteriorly threaded below as at al to screw into the cylinder head, or as shown in Fig. 7 into a cupped bush a2 which in turn is screwed v'into said cylinder head. The member o, which may be aptly termed the valve seat member, is interiorly screw-threaded at the top at c3 to receive the lower threaded end 1 Vof the valve member b which has a part conical bore b2 from which extend a plurality of radial apertures if leading to the exterior, three of such apertures being illustrated in Fig. 6. At its upper end the valve member is interiorly threaded at b4, vand exteriorly flattened as at b5 to hexagonal form for reception of a wrench, Spanner or the like. A

Within the valve member I) and lower member a. is inserted the insulated electrode comprising any conventional form of metallic or other conductor c surrounded by insulating material c] and provided above with the usual terminal screw c2 for attachment of theconductor c3 (Fig. 7

The said insulated electrode is provided about midway its length with a collar or enlarged portion c4 which bears upon a shoulder Z9 within the bore of the valve member l), and the electrode is secured in place in said member b by a threaded bush or gland which screws into the threaded upper end b4 of member l).

To the upper end of valve seat member a is secured a comparatively shallow cup (l, which on rotation of the valve member in member a; and consequent lifting of said member l will communicate with the apertures b in member b as shown in Fig. 2'. c designates the usual ground electrode'carried by the valve seat member a. with conductor or electrode c forming the spark-gap, and in Fig. 7 f designates the cylinder head, g the water jacket and h a valve in said cylinder head.

lVith a plug constructed as above described the operation is as follows: With the parts in the position shown in Fig. l the deviceacts normally as a sparking plug only, but when it is desired to prime the cylinder with liquid fuel, the valve member Z9 is screwed back as by means of a wrench applied to the hexagonal faces b5, thus raising said member Z) and with it the insulated electrode 0 c1 to the position shown in Fig. 2 in which as aforesaid the apertures b3 com municate with the cup CZ, and with the atmosphere.

It will also be noted that the lower conical part of the insulated electrode does not make a close fit with the coned inner bore b2 of the valve member b but that there is left between these parts at all times an annular space z, through which liquid fuel poured into the cup CZ and passing through the apertures b3 can flow by gravity downwards and through valve seat member a, into thel cylinyder to prime same.

The priming effect will thus take place all round the insulated electrode and not through or only to one side thereof as in some known constructions, and as in this position of the parts the cylinder is open to the atmosphere through member a., annular channel t', apertures Z13 and cup (Z, the air or gases under pressure in the cylinder due to starting or cranking up of the engine will flow or blo-w b-ackto the atmosphere, as

l indicated by the arrows in Figs. 2 and 7, and

will dislodge or remove any oil or solid particles such as carbon, which collect on the electrodesand insulation and thus keep these parts clean and in serviceable condition. The screwing back of the valve member I) also carries with it the insulated electrode c c1 by reason of the engagement or' the collar 04 and shoulder 6G and this Vmovement of said insulated electrode when opening the plug also assists in dislodging deposits from the spark gap which is therefore not constant except when the valve is closed.

v l/Vhat I claim as my invention and desire to secure by Letters Patent of the United States is l. A sparking plug comprising a hollow valve seat member adapted to be itted to an associated cylinder, a radially apertured valve member screwed thereinto, an insulatedelectrode within said valve member and movable therewith, and a stationary cup for receiving priming liquid, and open to the atmosphere, said cup being shut on' from the apertures in the valve member when the parts are in normal position but open thereto when said valve member is moved relatively to the hollow valve seat member. V

Y 2. A spark plug comprising a hollow valve seat member carrying a grounded electrode, a radially anertured valve member movable relatively thereto, an insulated electrode positioned within the valve member and within the hollow valve seat member and leaving an annular chamber therebetween, and a cup open tothe atmosphere and Vsurrounding the valve member and adapted to receive priming liquid, said valve member serving, in one position, to close communication between the interior of the hollow7V valve seat member and theatmosphere, and, in another position, toplace the interior of said valve seat member in communication with the atmosphere through the apertures in the valve member and through the cup aforesaid. f

3. A sparking plug comprising a tubular valve Vseat member provided vat substantially its upper edge with a, valve seat, and an an-v nularpriming cup surrounding said valve seat, in combination with a Itubular valve member one end portion of which is eX- teriorly threaded to screw into the interior of the valve seat member and which threaded portion terminates 1in an annular channel through the base of which a plurality of radial apertures are formed in the wall of the valve member, a shoulder adjacent said channel and constituting a valve adapted for cooperation Vwith the valve seat or' the valve. seat member to control communication'between the priming cup and the interior oil the plug, an annular shoulder on the interior of the valve member, an insulating member provided intermediate its ends with an enlargement adapted to seat upon this shoulder, a bush threaded into the valve member to engage with the enlargement of the insulating member and clamp said enlargement tightly to4 the shoulder within the valve member, and an electrode extending co-aXially through and carried by` the insulating member, that portion of the insulating member fbelow the enlargement being of reduced section to leave an'annular channel between such portion and the wall of the valve member, so that when the valve member is in position to unseat the valve unrestricted communication is provided between the; interior of the plug and the priming cup. f

AIn witness whereof Ihave signed this specification.

MALCQLMALLAN GRAY. 

